Ch 34 - Coagulation Disorders Flashcards
Phases of platelets (4)
adhesion
aggregation
secretion
cross-linked of adjacent platelets
Thrombogenesis (blood vessels)
vasocontriction
formation of platelets plugs
regulation of coagulation and fibrinolysis
Blood coagulation (3 components)
extrinsic pathway
intrinsic pathway
thrombin activation
Extrinsic pathway
Tissue damage exposes tissue factor
intrinsic pathway
Platelets interact with damaged endothelium
thrombin activation
formation of fibrin clot
Virchow’s Triad
stasis (decreased BF)
hypercoagulability (blood clot are likely)
endothelial injury (damage of inside of blood vessel)
White thrombus
high-pressure arteries (abnormal endothelium)
arterial flow
fibrin formation
downstream ischemia
red thrombus
low-pressure veins
red cell around white thrombus
long tail
detachment
PE
DVT risk factors (inherited)
anti-thrombin III deficiency
Protein C & S deficiency
sickle cell anemia
activated protein C resistance
DVT risk factor (Acquired)
bedridden
surgery/trauma
obesity
estrogen use
malignancies
chronic venous insufficiency
regulation of coagulation (2 systems)
Fibrin inhibition
fibrinolysis
Protease inhibitors (4)
alpha 1 - antiprotease
alpha 2 - macroglobulin
alpha 2 - antiplasmin
antithrombin
Fibrinolytic system function:
-Convert (inactive) plasminogen to plasmin(active)
Thrombotic disease therapy
t-PA
urokinase
streptokinase
Aminocaproic Acid
protect clots from lysis
What type of thrombus is associated with a high pressure vessel (i.e. artery)?
White Thrombus (No RBCs, just fibrin)
What two factors are exposed by injury leading to platelet adherence & activation?
-Exposed Collagen
- Von Willebrand Factor
What type of thrombus is associated with a low pressure vessel (i.e. vein)?
Red Thrombus (RBC + fibrin)
What do platelets release that. causes local vasoconstriction?
Serotonin
What type of thrombus would you expect to see associated with Coronary Artery Disease? Why?
White Thrombus (high pressure vessel, no RBCs)
Detachment of Red thrombi typically leads to what complication?
Pulmonary Embolism
DVT risk factors can be _________ and/or _________.
Inherited; acquired
What are some examples of acquired DVT risk factors?
Bedbound
Surgery/trauma
Obesity
Estrogen use (birth control typical)
Malignancies
What common form of transportation is a risk factor for DVT formation? How is this prevented?
-Airplane flights
-Getting up, stretching, flexing lower extremities.
What is DIC? Why does this occur?
What results from this condition?
-Disseminated Intravascular Coagulation
-Completely used up blood clotting factors
-Excessive spontaneous bleeding is the result.
What are four common causes of DIC?
What are the treatments?
1.Massive tissue injury
2.Malignancy
3.Bacterial Sepsis
4. Abruptio Placentae
Plasma transfusion & treatment of underlying cause.
What is the mortality of DIC?
10-50%
How is overcoagulation avoided by our body’s internal mechanisms?
Regulation of Coagulation via:
- Fibrin Inhibition
- Fibrinolysis
What enzyme converts plasminogen to plasmin?
What is the purpose of this conversion?
- tPA (tissue Plasminogen Activator)
- Plasmin actually breaks down the clot itself
